The owner's manual is not helpful here; do I need to do anything differently when I run this amp sending CW. I already send a tone when I tune for SSB, but amps list different max. output with CW and RTTY and AM and I am unclear if there is something I need to dial back or if the amp just puts out less as a result of the signal in.

I always just tune the amp for maximum power out ( that where the dip and peak points are, ) keeping it under 700 mills, and then turn the power down on the radio a tad so you are not pushing it for every stinkin watt you can get. they cannot hear the difference between 400 and 6oo watts on the other end. so input 35 or 40 watts for 400 -600 out, depending on band an antenna and enjoy.

I would suggest that you read the manual. It reads 600 watts for CW. It also reads full load is 700 Ma.for the power supply. Forget the 700 ma and load the amp with a watt meter, then make sure you are not exceeding 700 Ma. I for one have used Ameritron amps for over 20 years with no complaints. Even the three tube 811 is a jewell if used as the manual dictates. To summarize, load the 811H up in the CW mode for a max of 600 watts using a watt meter according to the manual. Bang away on CW, just not too fast.

Tim,If you read W8JI's supplement notes to tuning the 811H, it reads to the effect that the 750 Ma carrier should be of short duration. I perceive that to be tuning up quickly, and not actual operating current as that exceeds the supply rating and tube rating. Trying to tune without a watt meter is a venture for disaster. So many newbies I have read are simply trying to tune with the amp's meters, not for watt meter power out within the max current ratings for grid and plate currents. Just my opinion, certainly not a known fact or endorsed by W8JI to my knowledge.

Tim,If you read W8JI's supplement notes to tuning the 811H, it reads to the effect that the 750 Ma carrier should be of short duration. I perceive that to be tuning up quickly, and not actual operating current as that exceeds the supply rating and tube rating. Trying to tune without a watt meter is a venture for disaster. So many newbies I have read are simply trying to tune with the amp's meters, not for watt meter power out within the max current ratings for grid and plate currents. Just my opinion, certainly not a known fact or endorsed by W8JI to my knowledge.

Frank

The problem is not the power supply but rather the tubes as they can go into melt down quickly at 750ma as 811 can only dissipate 45 watts per tube continuous and 65 watts intermittently safely. A 750ma tun well exceeds these rating is is kinda like playing Russian roulette with most of the chambers loaded.

Logged

--------------------------------------Ham since 1969.... Old School 20wpm REAL Extra Class..

Mfgs like Heath, Gonset, Collins and Ameritron have pushed 811A tubes beyond their specs for many years. That is beyond my scope of understanding so I rely on the wisdom of those whom I think are in the know. Some good reading on the Ameritron 811 and 811h amps is here: The key is actual plate dissipation is a time intergrated product of anode current times voltage and includes power extracted by the load to determine the heating effect so I have read.Those who own the amps and are concerned might learn something from the designer if they read carefully and try to comprehend. May take a few times through, it did for me.http://www.w8ji.com/al811h_schematic.htm. As for me, when I need to replace my original tubes, I will go with the 572B tubes and crank my 811 up to 600 watts out on SSB.That way the tubes can take it and my power supply will be adequate for the 600 watts better than the 4 tube H model with 572 tubes and 800 watts out.

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